Ground-effect machine using steam as working fluid



Sept. 26, 1961 R. w. PINNES 3,001,500

GROUND-EFFECT MACHINE USING STEAM AS WORKING FLUID V 2 Sheets-Sheet 1 Filed Dec. 10, 1959 amen 1M ROBERT W PIA/MES Sept. 26, 1961 R. w. PINNES 3,001,500

GROUND-EFFECT MACHINE USING STEAM As WORKING FLUID Filed D60. 10, 1959 2 Sheets-Sheet 2 States of America as represented by the Secretary of the Navy Filed Dec. 10, 1959, Ser. No. 858,838 Claims. (Cl. 114-67) (Granted under Title 35, us. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

The present invention relates to ground-effect machines operable over water and more particularly to a groundeiiect machine using steam as a working fluid.

The general concept of a conventional ground-effect machine is not new. Broadly, a ground-eflect machine 18 a device designed to utilize the phenomenon of ground-effect. This ground-efiec phenomenon is based upon the fact that when an annular jet is dis-. charged downwardly from the base of a device in relatively close proximity to the ground, a lift force greater than the jet reaction force will be realized. This added lift is a product of the creation of a high-pressure air bubble beneath the base of the device. In this manner the device or machine actually rides on a cushion of air.

It should be readily appreciated that operation in proximity to the surface of the ground or water (or ice or snow) is a prime requisite for any device designed as a ground-effect machine. The mouth or exit from which the jet discharges need not be truly annular so long as it is in the shape of a closedplane curve or even polygonal in shape.

In contrast to the conventional ground-effect machine which employs air as a working fluid the present invention is a ground-eflect machine designed to operate over bodies of water and employing steam as a working fluid. The water necessary to produce the steam is withdrawn from the body of water over which the machine operates. In such an improved device a pump and drive therefor are the only moving parts, the fan of the conventional ground-effect machine having been replaced by a pump for drawing up the water and circulating it at the required pressure. In addition to producing a simpler, lighter machine, the use of a pump instead of a fan will completely eliminate fan stall and surge problems.

Therefore, an object of the present invention is to produce a simpler, lighter ground-efliect machine for operation over water.

Another object is to produce a ground-efleot machine fflor operation over water employing steam as a working A further object is the provision of a ground-eifect machine for operation over water, which machine employs steam as the working fluid withdrawing the necessary water therefor from the body of water over which it operates.

Still another object is to provide a ground-effect machine for operation over water employing steam and induced air as the working fluid.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a transverse section through a conventional ground-effect machine;

FIG. 2 shows a transverse section taken through a ground-effect machine embodying the present invention;

,FIG. 3 shows a plan view of a groundelfect machine iddifidit embodying a steam ejector as a variation of the present invention;

FIG. 4 is a section taken on line 44 of FIG. 3;

FIG. Sis a plan view of a variation of the steam ejector shown in FIGS. 3 and 4 employing the Coanda nozzle with the steam nozzle arranged about the outer periphery of the duct;

FIG. 6 is a section taken on line 6-6 of FIG. 5;

FIG. 7 shows a plan view of a second construction employing the Coanda nozzle with the steam nozzle arranged about the inner periphery of the annular duct; and

FIG. 8 is a section taken on line 8-8 of FIG. 7.

Referring now to the drawings, FIG. 1. shows a conventional ground-eflect machine 11 hovering over surface 12. In operation, air is drawn through intake or duct 13 into exterior housing 14 by ducted fan 16 and is pumped down through vertical well 17 to be discharged from annular nozzle 18 as indicated by the arrows.

Annular jet 19 serves the dual function of creating and maintaining a groundcushion regime in the region 21 beneath base 22. Although jet 19 tends to entrain air both from region 21 and from the ambient air, when the jet impinges on the surface 12, part of the jet air is fed back into region 21 replacing the air lost therefrom due to entrainment. In this way a ground-cushion of air is contained by jet 19 to support machine 11. FIG. 1 shows a simple machine with only one fan 16 and one engine 23 (with clutch and reduction gear unit 24) however, the same discussion applies to a larger machine using a multiplicity of fans and engines.

In contrast to machine 11 which employs air as the working fluid the ground-effect machine 31 shown in FIG. 2 employs steam alone as the working fluid and requires neither fan nor clutch and reduction gear. Outer housing 32 has an inner housing 33 arranged therein and spaced therefrom so as to provide vertical duct 34 and annular nozzle 35. A tube 36 depends from inner housing 33 with its open end below the surface 37. This tube is called a lekrons (snorkeF spelled backwards). Tube 36 is always maintained as shown with its lower end below the surface. Water is drawn into tube 36 and pumped up-by pump 38. This water is then passed under pressure from pump 38 through heat exchanger means 39 connected with heat source 41 where is is vaporized and superheated as desired. Heat source 41 can be any conventional heat source, of course, but a nuclear reactor would be veiy desirable. Once the water has been changedto steam by evaporation this steam passes through annular duct 34 since this is its only path of release and is ejected from nozzle 35 to provide the ground-eflect lift. Details of water pump 38 and heat source 41 are not given since these would be conventional units. Power for pump 38 could be provided by a turbine (not shown) being operated by some of the steam produced in heat exchanger 39. In the event that salt water is used to generate steam the problem of salt deposit must be provided for. One possible solution would be to have dual evaporating coils (not shown) in heat exchanger 39. If conventional boilers (not shown) are used with a conventional heat source a dual boiler system can be used. Thus, one set of evaporating coils or one boiler could be in the process of being washed out with sea water to remove salt deposits, while the other set of coils or duplicate boiler is being used to produce steam. After a suitable length of time the units could be switched.

As seen from FIG. 2 the steam produced by the machine itself is the sole working fluid. By a change in the construction as shown in FIGS. 3 and 4 the steam produced as in FIG. '2. can be used as the primary jet in an ejector system. Thus, ground-effect machine 51 has an outer housing 52 and an inner housing 53 arranged therein and spaced therefrom to create annular passage 54 and annular nozzle 56. Tube 57 projects downwardly from the inner housing 53. Pump 58 is arranged within inner housing 53 at the upper end of tube 57. Water is drawn up into tube '57 by pump 58 and is forced under pressure through heat exchanger 59 connected to heat source 61 where the water is vaporized and superheated. The steam then is forced under its own pressure up through conduit 62 and out a series of individual jet nozzles 63. These jets of steam directed downwardly into annular passage 54 and out nozzle 56 function as the primary jets in an ejector system whereby ambient air'is induced into annular passage 54 through throat 64. The combined flow of steam and air then flows out nozzle 56 to provide the ground-effect lift phenomenon. A sufficiently large number of jet nozzles 63 are employed to insure a uniform induced air flow.

FIGS. 5, 6, 7 and 8 disclose variations of the'steam ejector configuration shown in FIGS. 3 and 4. Both variations employ the Coanda nozzle, the variation shown in FIGS. and 6 having the steam nozzle 71 formed in the outer periphery of annular passage 72 in outer housing 73. Annular passage 72 being bounded by outer housing 73 and inner housing '74. Tube 76, pump 77, heat exchanger 78 andheat source 79 function in the same manner as previously described. Steam generated in heat exchanger 78 passes through steam supply tubes 81 to annular supply conduit 82 from which the steam is directed downwardly into annular passage 72 by circumferential nozzle 71. Induction of ambient air by such a system is more desirable due to the complete axial symmetry of the ejector system. The remainder of the operation is as set forth with regards to FIG. 3.

The variation employing the Coanda nozzle shown in FIGS. 7 and 8 differs from the one described in FIGS. 5 and 6 in that steam nozzle 91 is formed in the surface of inner housing 92. This, of course, necessitates a different contour for inner housing 92 but the elements of the structure remain unchanged; namely, outer housing 93, annular passage 94, tube 96, pump 97, heat exchanger 98, heat source 99, steam supply tubes 101 and annular supply conduit 102. In operation, this structure is the same as that in FIGS. 5 and 6. If desired, of course a combination of these two structures can be effected.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In a ground-eifect machine for operation over water having an exterior housing and an interior housing arranged within said exterior housing, sustaining means comprising in combination intake means projecting from the inner housing of said machine, said intake means connecting the interior of said inner housing with the water below said machine, means mounted within said inner housing connected to-said intake means for pumping water up from below said machine, evaporating means communicating with said pumping means, said pumping means forcing said water under pressure into said evaporating means, whereby steam is generated therefrom, and means for directing said steam downwardly to exit from a nozzle having the exit portion thereof in the shape of a closed plane curve adjacent the base of said interior housing, said last-named means comprising a plurality of tubes leading from said evaporating means and terminating innozzle jets, a duct formed between the interior and exterior housings, said nozzle jets being directed downwardly into said duct, said duct communicating with the atmosphere above said machine.

, means, whereby steam is generated therefrom, and means for directing said steam downwardly to exit from a nozzle having the exit thereof in the shape of a closed plane curve adjacent the base of said interior housing, said lastnarned means comprising a plurality of tubes leading from said evaporating means, an annular duct having an annular steam nozzle as an exit therefrom, said tubes discharging into said duct, said steam nozzle being directed downwardly, a vertical duct formed between said interior and exterior housings, said annular steam nozzle discharging into said vertical duct, said vertical duct communicating with the atmosphere above.

3. In a ground-eifect machine for operation over water comprising in combination an exterior housing, an interior housing arranged within said exterior housing and spaced therefrom to form a downwardly directed vertical duct having a nozzle the mouth of which is in the shape of a closed plane curve, a tube projecting downwardly from said inner housing with the lower end of said tube extending below the surface of the water, means mounted within said inner housing connected to the upper end of said tube for pumping water up and forcing said water under pressure into evaporating means, whereby steam is generated therefrom, and means for directing said steam downwardly through said nozzle, said last-named means comprising a plurality of tubes leading from the evaporating means, an annular conduit located above the downwardly directed vertical duct, said tubes discharging into said annular conduit, said annular conduit having a downwardly directed steam nozzle as an exit therefrom and said vertical duct communicating with the atmosphere above said machine whereby when steam is forced from said steam nozzle such steam passes down through said vertical duct inducing thereby the flow of ambient'air whereby both air and steam are directed downwardly through said vertical duct to sustain said machine.

4. A ground-effect machine as recited in claim 3 wherein the annular conduit is substantially horizontally disposed about the outer periphery of the vertical duct approximately where said vertical duct communicates with the atmosphere above the machine.

5. A ground-effect machine as recited in claim 3 wherein the annular conduit is substantially horizontally disposed about the inner periphery of the vertical duct approximately where said vertical duct communicates with the atmosphere above the machine.

References Cited in the file of this patent UNITED STATES PATENTS 1,017,564 Lake Feb. 13, 1912 1,838,354 Bauer Dec. 29, 1931 1,938,234 Voorhees Dec, 5, 1933 FOREIGN PATENTS 219,133 Australia Nov. 24, 1958 795,517 France Jan. 8, 1936 OTHER REFERENCES American Helicopter, January 1957 (page 7 relied on). 

